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Building the City of West Palm Beach’s Stormwater Infrastructure Rehab Program
June 15, 2018
Presentation Outline
Data Evaluation and Literature Review
Condition Assessment Methodologies and Decision Logic
Rehabilitation Methodologies and Decision Logic
Next Steps
Questions
01 Data Evaluation and Literature Review
City’s policies, activities, and processes
Stormwater Master Plan and project
recommendations
Geodatabase of storm sewers
FDOT manuals and specifications
Compile list of storm sewer inspection and
rehabilitation bids
Contractor interviews
Data Evaluation and Literature Review
60 square mile watershed
600 sub-basins
186 miles of storm pipe, up to 96” diameter
Pipe materials
o 60% reinforced concrete (RCP)
o 16% vitrified clay (VCP)
o 7% corrugated metal (CMP)
Stormwater Asset Summary Data Evaluation and Literature Review City of West Palm Beach Stormwater System
Budgeting tool for future work
Data grouped by pipe diameter and location
(Florida, regional, and national)
Costs obtained for:
o CCTV inspection
o Pipe cleaning
o CIPP lining
o Sliplining
Data Evaluation and Literature Review Storm Sewer CCTV Inspection and Rehabilitation Bids
National Association of Sewer Service
Companies (NASSCO) rating system can
effectively be applied to storm sewers
Cured-in-place pipe (CIPP) lining is the
preferred option for repairs, as it can be
installed in larger runs and larger diameters
Data Evaluation and Literature Review Interview with Local Contractors
Challenges of working in a coastal
environment:
o Cleaning barnacles/heavy
sedimentation, and working in water to
inspect/repair outfalls due to boat traffic
o Extensive dewatering required due to
high groundwater table
o Working in tidally-influenced areas
makes work possible at only certain
times of the day
Data Evaluation and Literature Review Interview with Local Contractors
02 Condition Assessment Methodologies and Decision Logic
Cleaning requirements
Dewatering and bypass pumping requirements
Condition assessment technology options
Decision model
Condition rating scale
Technical specifications
o Inspection equipment requirements
o Inspection data and reporting requirements
Condition Assessment Methodologies and Decision Logic
Mechanical
o Rodding – primary application is small diameter pipe
o Bucket machine – typically cylindrical drive with jaws to pull debris from pipe or structure
Hydraulic
o Jetting – high velocity water used to wash sediment from pipe; typically used on smaller diameter pipe in
parallel with vacuum truck
Condition Assessment Methodologies and Decision Logic Cleaning Requirements
If water level is greater than 10 to 20 percent of pipe diameter, dewatering is required to
complete a comprehensive inspection using conventional CCTV
Submerged or partially submerged pipes require an upstream and downstream plug
Bypass pumping may be required if upstream segment of pipe surcharges and has potential to
cause surface flooding
Condition Assessment Methodologies and Decision Logic Dewatering and Bypass Pumping Requirements
Closed Circuit
Television
(CCTV)
Subaqueous
CCTV
Zoom Camera
Laser Profiling
Sonar
Condition Assessment Methodologies and Decision Logic Technology Options
Tier 1: Preliminary
Inspection
• Qualitative screening
• No condition rating
• Technology
o Subaqueous CCTV
o Zoom camera
Tier 2: Condition Assessment
• Detailed visual inspection over length of
asset
• Produces structural and O&M condition
rating
• Data can be used to define limits of more
intensive Tier 3 inspections
• Technology
o CCTV
(convention or subaqueous)
o Zoom camera
(for manholes/inlets)
o Visual inspection
(for large culverts)
Tier 3: Inspection to Support
Engineering Design Activities
• Detailed data inputs for
engineering analysis to define
appropriate rehab technique
• Technology
o CCTV
o Laser profiling
Condition Assessment Methodologies and Decision Logic Tiered Approach for Inspection and Decision Logic
Recommend
applying a modified
version NASSCO
condition rating system
for the City’s stormwater
assets to standardize the
inspection process
Rating scale takes into
account number, type,
and severity of defects
Condition Assessment Methodologies and Decision Logic Condition Rating Scale
Inspection equipment and software
technical requirements
o CCTV camera
o Camera for manhole/inlet inspections
o Zoom camera for inspection
o Compatibility with City’s current CCTV
software (GraniteNet)
Data and reporting requirements
o Data acquisition (mandatory fields)
o Video, images, and measurement
o Deliverables
o Quality control and acceptance of
deliverables
Condition Assessment Methodologies and Decision Logic Technical Specifications
03 Rehabilitation Methodologies and Decision Logic
CIPP lining
Sliplining
Grouting
Pipe bursting (replacement)
Open cut (replacement)
Rehabilitation Methodologies and Decision Logic Technical Specifications
Plugging
Bypass pumping
Mechanical/hydraulic cleaning
Coffer damming (outfalls)
Rehabilitation Methodologies and Decision Logic Guidance for Technical Issues
Key components
o Insertion of a liner impregnated with thermosetting
resin within an existing host pipe
Advantages
o Fully structural replacement
o Small reduction in cross-sectional area – minimal
impact to hydraulics
o No entrance or exit pits required – minimal surface
disruption
Disadvantages
o Dewatering/bypassing required during construction
o Sometimes more costly compared to other lining
methods
Rehabilitation Methodologies and Decision Logic Rehabilitation Method: Cured-in-Place Pipe (CIPP) Lining
1. Plan and
Prioritize
Inspections
2. Conduct
Field
Inspections
3. Analyze Data
and Generate
Initial
Recommendations
4. Develop and
Execute
Improvement
Projects
5. Leverage Data
To Manage
Assets
Rehabilitation Methodologies and Decision Logic Condition Assessment Programs: Typical Workflow
Failure History
Decision
Process
Maintenance
Type &
Frequency
Repair
Rehabilitate
Replace
Inspections and
Condition Data
Maintenance
History
Rehabilitation Methodologies and Decision Logic Develop High-Quality Decision Process
Key Questions or Decision Points that influence implementation
Key Questions / Decision Points Impact on Decision Logic
Was a defect requiring rehab identified during inspection? If yes, enter rehab decision logic
Has storm sewer been identified as being undersized? If yes, pipe bursting or open cut required
Frequency of point defects? If high frequency, consider lining rather than point repair
What is the existing pipe material? Impacts feasibility of certain rehab methods
What is the existing pipe size? Impacts feasibility of certain rehab methods
Is existing pipe deformed or sagging? Open cut may be required
What are surface conditions above existing pipe? Open cut may be less cost-effective
04 Next Steps
Inspect priority 5,000 LF of storm sewer and review submittals
Select rehabilitation approach using decision model
Rehabilitate storm sewers included in pilot project
Incorporate lessons learned from pilot to methodologies and decision logic
Apply methodologies and decision logic to remaining 35,000 LF of priority storm sewer
Next Steps
